Light sensitive diazotype materials



United States atent O 3,028,240 LIGHT SENSITIVE DIAZOTYPE MATERIALS Georg Werner, Wiesbaden-Biebrich, and Gottlieb von Poser, Wiesbaden, Germany, assignors, by mesne assignments, to Keutfel & Esser Co., Hoboken, NJ. No Drawing. Filed Jan. 15, 1959, Ser. No. 786,920

Claims priority, application Germany Jan. 18, 1958 14 Claims. (Cl. 96-91) This invention relates to light sensitive diazotype ma terials. More specifically, it relates to diazotype materials of the one component type.

In diazotype processes used for the-reproduction of documents, two methods of development are used, the so-called dry development with gaseous ammonia and the so-called semi-wet development with alkaline solutions containing among other things the azo-dye coupling component or coupler. Consequently, there are also two types of light sensitivematerial suitable for the diazotype reproduction processes, namely, two component material for the dry development process and one component material for the wet development process. It is understood that the two essential components are the light sensitive diazo compound and the azo dye coupling component. In the case of the semi-wet materials, the azo dye coupling component is present in the developer but not in the light sensitive material. Principally, only four groups of the many classes of diazo compounds proposed for the wet development process have become of practical importance. These are the following:

(1) Diazo compounds of the phenylene diamine series in which the hydrogen atoms of the amino group in the para position are substituted by, for example, an ethyl group and a benzyl group.

(2) Diazo compounds of the type Blue Salt BB, having the formula:

which give prints rich in contrast and of good light stability but are not all that could be desired as regards light sensitivity.

(3) Diazo compounds of the diphenyl series without amino group, of the type R=C2H5 (4) Sulphur-containing diazo compounds of the type 0 R Q Q I R=CH3 or C2H5 Now one-component diazotype material has been found which is admirably suited to the wet-development process. It includes a diazo compound which has a suitably high light sensitivity about twice as high as the types included under 1, 2 and 4 above as well as a suitably high coupling capacity and a relative low water solubility so it will not run or bleed in the developing solution. Furthermore, a diazo compound of the class of the present invention can be used to form the m'uchpreferred blackline. prints.

ice

This can be accomplished with developers which need not have an excessive pH and which are therefore stable.

The diazo compounds of the present invention are those corresponding to one of the following general formulae:

R, on

N NH: 5

C on

/ \N NH,

in which R represents an alkyl residue with straight or branched chain with, at least three carbon atoms and CH CH 0R O fir-C OR GHQ-CH2 HN N H:

The contrast of the copies produced with the papers according to the invention can be made even better by known additions to the light sensitive coating or by pretreatment of the paper with synthetic resin emulsions and/or finely divided silica or with casein and starch.

By selection of a suitable coupler for use with the developer from the couplers commonly'used in the art for the semi-wet process, blacks, browns, reds or blues can be produced as required. However, the developers which produce blacks are usually preferred. 1

Known diazo compounds resembling the diazo compounds of the invention but having alkoxy groups in the two and five positions in the benzene ring including only one or two carbon atoms are indeed-highly light sensitive, but, in the first place, their coupling capacity is inadequate for the semi-wet process and they are morewater soluble so that they tend to run or bleed making them more suitable for. the dry development process with ammonia, and, in the second place, with phloroglucinol developers they give only browns, instead of the desired blacks.

Examples 1 (1 Base paper of the kind commonly used for diazotype paper is coated with a solution containing in each liter of water 3 g. of gelatine g. of citric acid 5 g. of aluminum sulphate g. of glycol 10 cc. of alcohol g. of the zinc chloride double salt of the compound 4- diethylamino-2, S-di-n-butoxy-benzene-ldiazonium chloride and is then dried.

The light sensitive paper is exposed through a master to the light of a mercury vapor lamp. A direct copy is obtained which is developed to a bluish black image with the following developing solution:

17 g. of borax 14 g. of anhydrous sodium carbonate 14 g. of sodium thiosulphate 15 g. of sodium citrate, tertiary 40 g. of anhydrous sodium sulphate 4 g. of resorcinol 3 g. of phloroglucinol 0.4 g. of saponin In one liter of water.

The zinc chloride double salt of 4-diethyl-amino- 2, 5- di-n-butoxy-benzene-l-diazonium chloride is obtained as follows: I i

Aminohydroquinone-di-n-butylether is twice directly ethylated with diethyl sulphate, consecutively, without solvent. The oily diethylamino-bydroquinone-di-n-butylether thus obtained boils at 182-l85 C. under 9 mm. of mercury. This base is coupled in glacial acetic acid. The dyestufi' produced is isolated and subjected to reduction with sodium carbonate and hydrosulphite. The 4- amino-2,5-di-n-butoxy-diethylaniline thus obtained is diazotised and can be satisfactorily isolated in the form of, for example, the zinc double salt.

Similar good results are obtained, when instead of the zinc chloride double salt of the compound 4 diethyl amino 2,5 di-n-butoxybenzene l a diazoniumchloride, either the zinc chloride double salt of 4 di n propyl amino 2,5 di n butoxybenzene 1 diazonium chloride or the zinc chloride double salt of 4 dimethyl- :amino 2,5 n butoxybenzene 1 diazonium chloride, is used. All can be dissolved in the same manner and used for coating the base paper for diazotype material.

In the production of the zinc chloride double salt of 4 di n propyl amino di a n butoxybenzene 1 diazonium chloride, hydroquinone-di-n-butylether is nitrated in aqueous nitric acid. The nitro compound separates as a yellow oil, which is subjected to a vacuum distillation and which boils at a temperature of 208 to 209 C. at a pressure of a 12 mm. mercury. By catalytic reduction of the nitro compound, the corresponding amino compound is obtained, which boils in a vacuum at a temperature of 190 to 191 C. (9 mm. mercury). The two propyl groups at the nitrogen are introduced by heating the amino-hydroquinone-di-n-butylether obtained twice in succession; each time with an equivalent quantity of npropyl-bromide for several hours in a reflux condenser over a steam bath. The propylization product is separated irom the reaction mixture by means of a concentrated solution of potassium hydroxide (caustic potash) and is distilled in a vacuum. At a pressure of 9 mm. mercury, the boiling point of the dipropyl compound is 199 to 201 C. In order to completely remove the secondary base, the dipropyl compound is distilled once more over a small quantity of acetic acid anhydride. Subsequently 'the dipropyl compound is coupled in glacial acetic acid with a suitable diazotized aromatic amine, e.g. diazotized sulphanilic acid, to give a dyestufi. The separated dyethen diazotized with amylnitrite in absolute alcohol. The oily diazo compound is dissolved in water and separated by means of zinc chloride as a crystalline yellow zinc chloride double salt.

In the production of the zinc chloride double salt of 4 dimethyl amino 2,5 di -t n butoxybenzene 1 diazonium chloride, chloronitro hydroquinone di n-butylether is heated for 5 hours with an excess of dimethylamine to a temperature of C. in an autoclave. For purification, the reaction product is transformed into the corresponding hydrochloride, reconverted into the free base and finally recrystallized from alcohol. The purified reaction product melts at a temperature of 63 to 64 C. The nitro group is catalytically reduced in an autoclave and an oily base (boiling point 202 to 204 C. at 9 mm. mercury) is obtained. This base is diazotized in a solution of hydrochloric acid and by adding zinc chloride, the zinc chloride double salt is separated as a yellow powder.

(2) Instead of the diazo compound given in Example 1,

18 g. of Zinc chloride double salt of the compound 4- morpholino -2,5 di n propyoxy benzene 1 diazonium chloride 1 are added to the otherwise identical solution and witli this solution base paper is coated and made light sensitive in the usual manner. After exposure of this paper beneath a master black copies are obtained with the developer given in Example 1.

The diazo compound containing two butoxy groups instead of the two propoxy groups in the 2,5 positions can be used with equally good results for the preparation of the one-component coating.

The zinc chloride double salt of the 4 morpholino 2,5 di n propoxy benzene 1 diazonium chloride is prepared as follows:

Chlorohydroquinone-di-npropylether when nitrated with dilute nitric acid gives 4-chloro-l-nitro-hydroquinone-di-n-propylether (melting point 98-99 C.). This compound when boiled with aqueous morpholine gives 4-nitro-2,S-di-n-propoxyphenyl morpholine (melting point 109-110 C.). Reduction and diazotisation is carried out in known manner. The diazo compound is precipitated in the form of the zinc chloride double salt.

4 morpholino 2,5 di-n-butoxy-benzene-l-diazonium chloride can be prepared in analogous manner. The nitro component obtainable from the chlorhydroquinonedi-n-butylether by nitration with aqueous nitric acid melts at 8l-82 C. Here too the morpholine ring is introduced by simple heating of the chlornitro-hydroquinone-di-n-butylether with the base. The melting point of the 4-nitro-2,5-di-n-butoxyphenyl morpholine is about 101-102" C. Reduction and diazotisation follow.

(3) An aqueous solution (1 liter volume) of the following composition is coated onto paper:

2 g. of gelatine 4 g. of tartaric acid 5 g. of aluminum sulphate 10 cc. of triglycol 10 cc. of alcohol 22 g. of zinc chloride double salt of 4-piperidino-2,5-din-butoxybenzene-l-diazonium chloride.

When the one'component paper has been exposed under a master the copy is developed with a solution containing in one liter of water 15 g. of borax 15 g. of anhydrous sodium carbonate. 20 g. of sodium thiosulphate 35 g. of anhydrous sodium sulphate 5.5 g. of phloroglucinol.

For the preparation of the diazo compound given above the chloronitro-hydroquinone-di-n-butyl ether mendine. The resultant 4-nitro-2,5-di-n-butoxy-phenyl-piperidine melts at SO-81 C. Reduction is carried out with zinc dust, hydrochloric acid and a little alcohol. Diazotisation is accomplished in known manner.

Good results are also obtained when in the above described aqueous solution for coating paper, instead of the zinc chloride double salt of 4-piperidino-2,5-di-nbutoxy-benzene-l-diazonium chloride, the zinc chloride double salt of 4-piperidino-2,5-di-n-propoxy-benzene-1- diazonium chloride is used. This compound is produced analogously to the production of the zinc chloride double salt of 4-piperidino-2,S-di-n-butoxybenzene-l-diazonium chloride. The chloronitro-hydroquinone-di n propyl ether, mentioned in Example 2, is boiled for several hours with aqueous piperidine until the reaction is quantitatively complete (about 10 hours). The 4-nitro-2,5- di-n-propoxyphenyl-piperidine, which had been separated by diluting the reaction mixture with water, melts at a temperature of 80 to 81 C. The compound is reduced in hydrochloric acid to which a small quantity of ethyl alcohol has been added by means oi'zinc dust. The diazotisation takes place in aknown manner and results the crystallization of beautiful crystals of the zinc chloride double salt of the diazo compound.

3 g. of gelatine 5 g. of citric acid 20 cc. of triglycol cc. of alcohol g. of 4-morpholino-2,S-di-(isoamyloxy)-benzene-1-diazonium chloride are dissolved in 1 liter of water. Paper coated with this solution is characterized by high light-sensitivity. When the coated and dried paper has been exposed to light under a master the image produced is developed to form a deep black copy with the developer given in Example 1.

The above mentioned diazo compound is obtained as follows:

Sulphuryl chloride is poured upon hydroquinone-diisoamylether, equimolecular quantities +50% excess chloride being used. Reaction takes place with copious evolution of HCl and S0 The product of the reaction is allowed to stand overnight and then subjected to vacuum distillation in which the chlorhydroquinone-diisoamyl ether goes over as a liquid at 184-187 C. under 10 mm. of mercury. The 4-chloro-l-nitro-hydroquinonedi-isoamyl-ether-2,5, which is readily obtainable therefrom by nitration, is heated to boiling with aqueous morpholine for some time. The 4-nitro-2,5-di-(isoamyloxy-phenyl)-morpholine that crystallizes out is isolated, reduced and diazotised. This compound is preferably precipitated in the form of the hydrochloride because the zinc salt is insufiiciently soluble.

Instead of 4-morpholino-2,5-di-(isoamyloxy)-benzenel-diazonium chloride, either of the homologous diazo compounds may be used, which in the 2,5 positions contain two isobutoxy groups or two isopropoxy groups, respectively, instead of the two isoamyloxy groups. Both compounds are prepared analogously to the preparation of the isoamyl compound described above.

Having thus described the invention what is claimed is:

l. A light sensitive diazotype material of the single component type comprising a base material coated with a light sensitive composition including a light sensitive diazo compound formed from a p-phenylenediamine having a general formula selected from the group consisting of:

and

C 0 R l (ER in which: R is alkyl containing 3 to 5 carbon atoms, R and R are alkyl groups containing 1 to 3 carbon atoms, and

c e V c is a saturated heterocyclic group selected from the group consisting of morpholinyl and piperidyl.

2. A light sensitive diazotype material of the single component type comprising a base material coated with a. light sensitive composition including a light sensitive diazo compound formed from a p-phenylene diamine of the general formula:

0R N NHz in which R is alkyl containing 3 to 5 carbon atoms, and

0 I l o is a saturated heterocyclic group selected from the group consisting of morpholinyl and piperidyl.

3. A light-sensitive one component diazotype material comprising a base material coated with a light'sensitive composition including a light-sensitive diazo compound which is the product of diazotization of a compound of the formula where is a saturated heterocyclic group selected from the group consisting of morpholinyl and piperidyl.

4. A light sensitive diazotype material of the single component type comprising a base material coated with a. light sensitive composition including a light sensitive diazo compound formed from a p-phenylenediamine of the general formula:

NHz

diazo compound of 4-morpholine-2,5-di-(isoamyloxy)- benzene-l-amine.

8. A light sensitive diazotype material of the single component type comprising a base material coated with a light sensitive composition including a light sensitive diazo compound of 4-morpholine-2,5-di-iso-butoXy-benzene-l-amine.

9. A light sensitive diazotype material of the single component type comprising a base material coated with a light sensitive composition including a light sensitive diazo compound of 4-morpholine-2,S-di-iso-propoxybenzene-l-amine.

10. A light sensitive diazotype material of the single component type comprising a base material coated with a light sensitive composition including a light sensitive diazo compound of 4-piperidino-Z,S-di-n-butoxy-benzenel-amine.

11. A light sensitive diazotype material of the single component type comprising a base material coated with a light sensitive composition including a light sensitive diazo compound of 4-piperidino-2,5-di-n-propoxy-benzene1-amine.

12. A light sensitive diazotype material of the single component type comprising a base material coated with a light sensitive composition including a light sensitive diazo compound of 4-diethylamino-2,5-din-butoxy-benzene-l-amine.

13. A light sensitive diazotype material of the single component type comprising a base material coated with a light sensitive composition including a light sensitive diazo compound of 4-din-propylamino-2,S-di-n-butoxybenzene-l-amine.

14. A light sensitive diazotype material of the single component type comprising a base material coated with a light sensitive composition including a light sensitive cliazo compound of 4-dimethylamino 2,5-di-n-butoxybenzene-l-amine.

References Cited in the file of this patent OTHER REFERENCES Brown: The Basis and Practice of the Diazotype Proc- 25 ess, Chemistry and Industry, Apr. 15, 1944, page 147.

UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No. 3,028,240 April 3, 1962 Georg Werner et a1.

It is hereby certified that error appears in the above numbered petent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, lines 44 to 48, strike out the following structural formula:

CH CH 0R HN N NH2 CH2 -CH2 (SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents 

1. A LIGHT SENSITIVE DIAZOTYPE MATERIAL OF THE SINGLE COMPONENT TYPE COMPRISING A BASE MATERIAL COATED WITH A LIGHT SENSITIVE COMPOSITION INCLUDING A LIGHT SENSITIVE DIAZO COMPOUND FORMED FROM A P-PHENYLENEDIAMINE HAVING A GENERAL FORMULA SELECTED FROM THE GROUP CONSISTING OF: 